crypto: mv_cesa - explicitly define kirkwood and dove compatible strings

We are about to add a new driver to support new features like using the
TDMA engine to offload the CPU.
Orion, Dove and Kirkwood platforms are already using the mv_cesa driver,
but Orion SoCs do not embed the TDMA engine, which means we will have to
differentiate them if we want to get TDMA support on Dove and Kirkwood.
In the other hand, the migration from the old driver to the new one is not
something all people are willing to do without first auditing the new
driver.
Hence we have to support the new compatible in the mv_cesa driver so that
new platforms with updated DTs can still attach their crypto engine device
to this driver.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>